If you are flying in from El Salvador, the closest major airports are Licenciado Benito Juarez International Airport, Querétaro Intercontinental Airport and General Francisco J. Mujica International Airport. In May, daytime highs in Mexico City are 30°C, while nighttime lows are 15°C. Finish your sightseeing early on the 11th (Fri) so you can travel back home.